Currently, flight devices like Unmanned Aerial Vehicles (UAV), due to the convenience and security thereof, have been widely used in fields such as agricultural production, geological survey, meteorological monitoring, power line inspection, rescue and relief aid, video shooting, map plotting and etc. In the control of the Unmanned Aerial Vehicle, the velocity detection and/or positioning control of the Unmanned Aerial Vehicle is/are key technology. Currently, the velocity detection and/or the positioning control of the Unmanned Aerial Vehicle are mostly done via the positioning realized by the global positioning system (GPS). In addition, currently the velocity detection and/or the positioning control of the Unmanned Aerial Vehicle are mostly performed by an algorithm based on a general scene.